elimination of black hole node using cluster

when i execute my code this error appear ,i have a problem in the nam so thats what i got
Warning: cannot open file `dsr_routing_3.tr'
Warning: cannot open file `dsr_routing_4.tr'
Nothing to plot.
Nothing to plot.
Warning: cannot open file `sink2.tr'
Warning: cannot open file `securedsr2.tr'
Warning: cannot open file `dsr2.tr'
Nothing to plot.
Warning: cannot open file `dsr_routing_2.tr'
Nothing to plot.
Warning: cannot open file `dsr_routing_6.tr'
Nothing to plot.
Warning: cannot open file `dsr1.tr'
Warning: cannot open file `securedsr1.tr'
Warning: cannot open file `sink1.tr'
Nothing to plot.
Warning: cannot open file `dsr_routing_1.tr'
Nothing to plot.
Warning: cannot open file `dsr_routing_5.tr'
Warning: cannot open file `dsr_routing_7.tr'
Nothing to plot.
Nothing to plot.
Warning: cannot open file `dsr3.tr'
Warning: cannot open file `sink3.tr'
Warning: cannot open file `securedsr3.tr'
Nothing to plot.
Parameter LabelFont: can't translate `helvetica-10' into a font (defaulting to `fixed')
Parameter TitleFont: can't translate `helvetica-18' into a font (defaulting to `fixed')
Cannot connect to existing nam instance. Starting a new one..